Answer:
a₁₅₇ = 1,088
Step-by-step explanation:
aₙ = a₁ + d(n-1); where 'd' if common difference
a₁₅₇ = -4 + 7(156)
= -4 + 1092
= 1,088
AC = √(40²-12²) = √(1600-144) = √1456 = 4√91
tanA = 12/4√91 = 3/√91 = 3√91/91
option а.
B. False
X and Y are two different variables.
If you evaluate directly this function at x=0, you'll see that you have a zero denominator.
Nevertheless, the only way for a fraction to equal zero is to have a zero numerator, i.e.

So, this function can't have zeroes, because the only point that would annihilate the numerator would annihilate the denominator as well.
Moreover, we have

So, we can't even extend with continuity this function in such a way that 